arch/metag/mm/init.c

   1 /*
   2  *  Copyright (C) 2005,2006,2007,2008,2009,2010 Imagination Technologies
   3  *
   4  */
   5
   6 #include <linux/export.h>
   7 #include <linux/mm.h>
   8 #include <linux/swap.h>
   9 #include <linux/init.h>
  10 #include <linux/bootmem.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/percpu.h>
  13 #include <linux/memblock.h>
  14 #include <linux/initrd.h>
  15 #include <linux/sched/task.h>
  16
  17 #include <asm/setup.h>
  18 #include <asm/page.h>
  19 #include <asm/pgalloc.h>
  20 #include <asm/mmu.h>
  21 #include <asm/mmu_context.h>
  22 #include <asm/sections.h>
  23 #include <asm/tlb.h>
  24 #include <asm/user_gateway.h>
  25 #include <asm/mmzone.h>
  26 #include <asm/fixmap.h>
  27
  28 unsigned long pfn_base;
  29 EXPORT_SYMBOL(pfn_base);
  30
  31 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
  32
  33 unsigned long empty_zero_page;
  34 EXPORT_SYMBOL(empty_zero_page);
  35
  36 extern char __user_gateway_start;
  37 extern char __user_gateway_end;
  38
  39 void *gateway_page;
  40
  41 /*
  42  * Insert the gateway page into a set of page tables, creating the
  43  * page tables if necessary.
  44  */
  45 static void insert_gateway_page(pgd_t *pgd, unsigned long address)
  46 {
  47         pud_t *pud;
  48         pmd_t *pmd;
  49         pte_t *pte;
  50
  51         BUG_ON(!pgd_present(*pgd));
  52
  53         pud = pud_offset(pgd, address);
  54         BUG_ON(!pud_present(*pud));
  55
  56         pmd = pmd_offset(pud, address);
  57         if (!pmd_present(*pmd)) {
  58                 pte = alloc_bootmem_pages(PAGE_SIZE);
  59                 set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)));
  60         }
  61
  62         pte = pte_offset_kernel(pmd, address);
  63         set_pte(pte, pfn_pte(__pa(gateway_page) >> PAGE_SHIFT, PAGE_READONLY));
  64 }
  65
  66 /* Alloc and map a page in a known location accessible to userspace. */
  67 static void __init user_gateway_init(void)
  68 {
  69         unsigned long address = USER_GATEWAY_PAGE;
  70         int offset = pgd_index(address);
  71         pgd_t *pgd;
  72
  73         gateway_page = alloc_bootmem_pages(PAGE_SIZE);
  74
  75         pgd = swapper_pg_dir + offset;
  76         insert_gateway_page(pgd, address);
  77
  78 #ifdef CONFIG_METAG_META12
  79         /*
  80          * Insert the gateway page into our current page tables even
  81          * though we've already inserted it into our reference page
  82          * table (swapper_pg_dir). This is because with a META1 mmu we
  83          * copy just the user address range and not the gateway page
  84          * entry on context switch, see switch_mmu().
  85          */
  86         pgd = (pgd_t *)mmu_get_base() + offset;
  87         insert_gateway_page(pgd, address);
  88 #endif /* CONFIG_METAG_META12 */
  89
  90         BUG_ON((&__user_gateway_end - &__user_gateway_start) > PAGE_SIZE);
  91
  92         gateway_page += (address & ~PAGE_MASK);
  93
  94         memcpy(gateway_page, &__user_gateway_start,
  95                &__user_gateway_end - &__user_gateway_start);
  96
  97         /*
  98          * We don't need to flush the TLB here, there should be no mapping
  99          * present at boot for this address and only valid mappings are in
 100          * the TLB (apart from on Meta 1.x, but those cached invalid
 101          * mappings should be impossible to hit here).
 102          *
 103          * We don't flush the code cache here even though we have written
 104          * code through the data cache and they may not be coherent. At
 105          * this point we assume there is no stale data in the code cache
 106          * for this address so there is no need to flush.
 107          */
 108 }
 109
 110 static void __init allocate_pgdat(unsigned int nid)
 111 {
 112         unsigned long start_pfn, end_pfn;
 113 #ifdef CONFIG_NEED_MULTIPLE_NODES
 114         unsigned long phys;
 115 #endif
 116
 117         get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 118
 119 #ifdef CONFIG_NEED_MULTIPLE_NODES
 120         phys = __memblock_alloc_base(sizeof(struct pglist_data),
 121                                 SMP_CACHE_BYTES, end_pfn << PAGE_SHIFT);
 122         /* Retry with all of system memory */
 123         if (!phys)
 124                 phys = __memblock_alloc_base(sizeof(struct pglist_data),
 125                                              SMP_CACHE_BYTES,
 126                                              memblock_end_of_DRAM());
 127         if (!phys)
 128                 panic("Can't allocate pgdat for node %d\n", nid);
 129
 130         NODE_DATA(nid) = __va(phys);
 131         memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
 132
 133         NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
 134 #endif
 135
 136         NODE_DATA(nid)->node_start_pfn = start_pfn;
 137         NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
 138 }
 139
 140 static void __init bootmem_init_one_node(unsigned int nid)
 141 {
 142         unsigned long total_pages, paddr;
 143         unsigned long end_pfn;
 144         struct pglist_data *p;
 145
 146         p = NODE_DATA(nid);
 147
 148         /* Nothing to do.. */
 149         if (!p->node_spanned_pages)
 150                 return;
 151
 152         end_pfn = pgdat_end_pfn(p);
 153 #ifdef CONFIG_HIGHMEM
 154         if (end_pfn > max_low_pfn)
 155                 end_pfn = max_low_pfn;
 156 #endif
 157
 158         total_pages = bootmem_bootmap_pages(end_pfn - p->node_start_pfn);
 159
 160         paddr = memblock_alloc(total_pages << PAGE_SHIFT, PAGE_SIZE);
 161         if (!paddr)
 162                 panic("Can't allocate bootmap for nid[%d]\n", nid);
 163
 164         init_bootmem_node(p, paddr >> PAGE_SHIFT, p->node_start_pfn, end_pfn);
 165
 166         free_bootmem_with_active_regions(nid, end_pfn);
 167
 168         /*
 169          * XXX Handle initial reservations for the system memory node
 170          * only for the moment, we'll refactor this later for handling
 171          * reservations in other nodes.
 172          */
 173         if (nid == 0) {
 174                 struct memblock_region *reg;
 175
 176                 /* Reserve the sections we're already using. */
 177                 for_each_memblock(reserved, reg) {
 178                         unsigned long size = reg->size;
 179
 180 #ifdef CONFIG_HIGHMEM
 181                         /* ...but not highmem */
 182                         if (PFN_DOWN(reg->base) >= highstart_pfn)
 183                                 continue;
 184
 185                         if (PFN_UP(reg->base + size) > highstart_pfn)
 186                                 size = (highstart_pfn - PFN_DOWN(reg->base))
 187                                        << PAGE_SHIFT;
 188 #endif
 189
 190                         reserve_bootmem(reg->base, size, BOOTMEM_DEFAULT);
 191                 }
 192         }
 193
 194         sparse_memory_present_with_active_regions(nid);
 195 }
 196
 197 static void __init do_init_bootmem(void)
 198 {
 199         struct memblock_region *reg;
 200         int i;
 201
 202         /* Add active regions with valid PFNs. */
 203         for_each_memblock(memory, reg) {
 204                 unsigned long start_pfn, end_pfn;
 205                 start_pfn = memblock_region_memory_base_pfn(reg);
 206                 end_pfn = memblock_region_memory_end_pfn(reg);
 207                 memblock_set_node(PFN_PHYS(start_pfn),
 208                                   PFN_PHYS(end_pfn - start_pfn),
 209                                   &memblock.memory, 0);
 210         }
 211
 212         /* All of system RAM sits in node 0 for the non-NUMA case */
 213         allocate_pgdat(0);
 214         node_set_online(0);
 215
 216         soc_mem_setup();
 217
 218         for_each_online_node(i)
 219                 bootmem_init_one_node(i);
 220
 221         sparse_init();
 222 }
 223
 224 extern char _heap_start[];
 225
 226 static void __init init_and_reserve_mem(void)
 227 {
 228         unsigned long start_pfn, heap_start;
 229         u64 base = min_low_pfn << PAGE_SHIFT;
 230         u64 size = (max_low_pfn << PAGE_SHIFT) - base;
 231
 232         heap_start = (unsigned long) &_heap_start;
 233
 234         memblock_add(base, size);
 235
 236         /*
 237          * Partially used pages are not usable - thus
 238          * we are rounding upwards:
 239          */
 240         start_pfn = PFN_UP(__pa(heap_start));
 241
 242         /*
 243          * Reserve the kernel text.
 244          */
 245         memblock_reserve(base, (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) - base);
 246
 247 #ifdef CONFIG_HIGHMEM
 248         /*
 249          * Add & reserve highmem, so page structures are initialised.
 250          */
 251         base = highstart_pfn << PAGE_SHIFT;
 252         size = (highend_pfn << PAGE_SHIFT) - base;
 253         if (size) {
 254                 memblock_add(base, size);
 255                 memblock_reserve(base, size);
 256         }
 257 #endif
 258 }
 259
 260 #ifdef CONFIG_HIGHMEM
 261 /*
 262  * Ensure we have allocated page tables in swapper_pg_dir for the
 263  * fixed mappings range from 'start' to 'end'.
 264  */
 265 static void __init allocate_pgtables(unsigned long start, unsigned long end)
 266 {
 267         pgd_t *pgd;
 268         pmd_t *pmd;
 269         pte_t *pte;
 270         int i, j;
 271         unsigned long vaddr;
 272
 273         vaddr = start;
 274         i = pgd_index(vaddr);
 275         j = pmd_index(vaddr);
 276         pgd = swapper_pg_dir + i;
 277
 278         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 279                 pmd = (pmd_t *)pgd;
 280                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
 281                         vaddr += PMD_SIZE;
 282
 283                         if (!pmd_none(*pmd))
 284                                 continue;
 285
 286                         pte = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 287                         pmd_populate_kernel(&init_mm, pmd, pte);
 288                 }
 289                 j = 0;
 290         }
 291 }
 292
 293 static void __init fixedrange_init(void)
 294 {
 295         unsigned long vaddr, end;
 296         pgd_t *pgd;
 297         pud_t *pud;
 298         pmd_t *pmd;
 299         pte_t *pte;
 300
 301         /*
 302          * Fixed mappings:
 303          */
 304         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 305         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 306         allocate_pgtables(vaddr, end);
 307
 308         /*
 309          * Permanent kmaps:
 310          */
 311         vaddr = PKMAP_BASE;
 312         allocate_pgtables(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP);
 313
 314         pgd = swapper_pg_dir + pgd_index(vaddr);
 315         pud = pud_offset(pgd, vaddr);
 316         pmd = pmd_offset(pud, vaddr);
 317         pte = pte_offset_kernel(pmd, vaddr);
 318         pkmap_page_table = pte;
 319 }
 320 #endif /* CONFIG_HIGHMEM */
 321
 322 /*
 323  * paging_init() continues the virtual memory environment setup which
 324  * was begun by the code in arch/metag/kernel/setup.c.
 325  */
 326 void __init paging_init(unsigned long mem_end)
 327 {
 328         unsigned long max_zone_pfns[MAX_NR_ZONES];
 329         int nid;
 330
 331         init_and_reserve_mem();
 332
 333         memblock_allow_resize();
 334
 335         memblock_dump_all();
 336
 337         nodes_clear(node_online_map);
 338
 339         init_new_context(&init_task, &init_mm);
 340
 341         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 342
 343         do_init_bootmem();
 344         mmu_init(mem_end);
 345
 346 #ifdef CONFIG_HIGHMEM
 347         fixedrange_init();
 348         kmap_init();
 349 #endif
 350
 351         /* Initialize the zero page to a bootmem page, already zeroed. */
 352         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 353
 354         user_gateway_init();
 355
 356         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 357
 358         for_each_online_node(nid) {
 359                 pg_data_t *pgdat = NODE_DATA(nid);
 360                 unsigned long low, start_pfn;
 361
 362                 start_pfn = pgdat->bdata->node_min_pfn;
 363                 low = pgdat->bdata->node_low_pfn;
 364
 365                 if (max_zone_pfns[ZONE_NORMAL] < low)
 366                         max_zone_pfns[ZONE_NORMAL] = low;
 367
 368 #ifdef CONFIG_HIGHMEM
 369                 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 370 #endif
 371                 pr_info("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 372                         nid, start_pfn, low);
 373         }
 374
 375         free_area_init_nodes(max_zone_pfns);
 376 }
 377
 378 void __init mem_init(void)
 379 {
 380 #ifdef CONFIG_HIGHMEM
 381         unsigned long tmp;
 382
 383         /*
 384          * Explicitly reset zone->managed_pages because highmem pages are
 385          * freed before calling free_all_bootmem();
 386          */
 387         reset_all_zones_managed_pages();
 388         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++)
 389                 free_highmem_page(pfn_to_page(tmp));
 390 #endif /* CONFIG_HIGHMEM */
 391
 392         free_all_bootmem();
 393         mem_init_print_info(NULL);
 394 }
 395
 396 void free_initmem(void)
 397 {
 398         free_initmem_default(POISON_FREE_INITMEM);
 399 }
 400
 401 #ifdef CONFIG_BLK_DEV_INITRD
 402 void free_initrd_mem(unsigned long start, unsigned long end)
 403 {
 404         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 405                            "initrd");
 406 }
 407 #endif